I had never observed the "Lunar X" before tonight. so decided to make an animation using my c11 while observing with an 8"dob. seeing was variable and it was bloody cold out. The lunar X is described as a clair-obscur effect which light and shadow create the appearance of the letter X. It appears on the rim of the Bianchinus, La Caille and Purbach craters.
https://media.giphy.com/media/l4FGCh...5Bf2/giphy.gif
Leigh